Biopsychology 151 test#3

For a normal person, about how long does a cycle of sleep (from stage 1 to stage 4 and back again) last?

90 minutes

Activation-synthesis hypothesis

A dream represents the brains effort to make sense of sparse and distorted information

Suprachiasmatic nucleus (SCN)

A part of the hypothalamus, damage to SCN the bodes rhythms become erratic. The SCN generates circadian rhythms itself in a genetically controlled manner. If SCN neurons are disconnected from from the rest of the brain or removed from the body and maintained in tissue culture, they continue to produce a circadian rhythm of action potentials.

Locus coeruleus

A small structure in the pons, is usually inactive, especially during sleep, but it emits bursts of impulses in response to meaningful events, especially those that produce emotional arousal.

Reticular formation

A structure that extends from the medulla into the forebrain. Some neurons of the reticular formation have axons ascending into the brain, some have axons descending into the spinal cord form part of the medial tract of motor control.

Basal forebrain

An area just anterior and dorsal to the hypothalamus. Cells provide axons that extend throughout the thalamus and cerebral cortex.

Activating effects

Are more temporary, continuing only while a hormone is present or shortly beyond

Alpha waves

At a frequency of 8 to 12 per second, characteristic of relaxation, not all of wakefulness.

Steroid hormones

Containing four carbon rings, can exert their effects in three ways, bind to membrane receptors, enter cells and activate certain kinds of proteins , bind to receptors that bind to chromosomes where they activate or inactivate certain genes.

Both sexual arousal and orgasm depend on the release of which neurotransmitter from the medial preoptic area neurons?

Dopamine

Alpha-fetoprotein

Early sensitive period, immature mammals have protein

Clinico-anatomical hypothesis

Emphasizes that dreams begin with arousing stimuli that are generated within the brain combined with recent memories and any information the brains receiving from the senses.

Follicle-stimulating hormone (FSH)

End of a menstrual period, the anterior pituitary releases, which promotes the growth of a follicle in the ovary. The follicle nurtures the ovum and produces several types of estrogen including estradiol.

Orexin or hypocretin

From the lateral and posterior nuclei of the hypothalamus, release a peptide neurotransmitter. Necessary for staying awake.

Congenital adrenal hypertrophy is most likely to have which of these effects?

Genetic female develops looking partly masculinized.

Hypothalamus

Histamine and orexin, increases arousal and maintains wakefulness

K-complex

Is a sharp wave associated with temporary inhibition of neuronal firing

Sexually dimorphic nucleus

Is larger in males than in females and contributes to control of male sexual behavior

Congenital adrenal hyperplasia (CAH)

Meaning overdevelopment of the adrenal glands from birth

Pontemesencephalon

One part of the reticular formation that contributes to cortical arousal. These neurons receive input from many sensory systems and generate spontaneous activity of their own. Their axons extend into forebrain and release acetylcholine and glutamate which excite cells in hypothalamus, thalamus and basal forebrain. Maintains arousal during wakefulness and increases it in response to new or challenging tasks

PGO waves

Rem sleep is associated with distinctive pattern of high-amplitude electrical potential

Dorsal raphe and pons

Serotonin, Interrupts REM sleep

SRY gene

Sex-determining region on the Y chromosome, causes those primitive gonads to develop into testes, the sperm producing organs. The testes produce androgens

What happens to a female human fetus exposed to excess testosterone during the sensitive period for genital development?

She will often develop with genitals that have an intermediate appearance.

TRUE OR FALSE: Girls with CAH are more likely to participate in "tomboyish" activities

TRUE

When studying disruptions to the biological clock in animals, what did Curt Richter find?

The biological clock is insensitive to most forms of interference.

According to the activation-synthesis hypothesis, what do dreams reflect?

The brain's attempt to make sense of spontaneous neural activity

What has been found in studies that relate male homosexuality in humans to prenatal stressors?

The findings are inconclusive.

Luteinizing hormone (LH)

The increased release of estradiol causes an increased release of estradiol causes an increased release of FSH as well as a sudden surge in the release of LH from the anterior pituitary. FSH and LH combine to cause the follicle to release an ovum.

An astronaut orbiting earth experiences 45-minute periods of daylight alternating with 45-minutes of darkness. What is likely to happen?

They sleep poorly during rest periods.

Suppose you work on a submarine with only artificial light. You are required to follow a schedule of working for 12 hours and then sleeping for 6. What rhythm, if any, will your alertness and body temperature show?

They will follow the usual rhythm of 24 hours.

The PER and TIM proteins accumulate during the day until they cause sleepiness. What prevents them from continuing to accumulate at night?

When the proteins reach a high level, they turn off the genes that produce them.

The most effective way to stimulate sexual behavior in a female rodent is to inject her with

a combination of estradiol and progesterone.

During an early sensitive period, a mammal is exposed to high levels of both androgens (such as testosterone) and estrogens (such as estradiol). How will its external genital anatomy appear

about like that of a normal male

The sexually dimorphic nucleus is part of the:

anterior hypothalamus.

Although harmful in excessive amounts, the synthesis of steroids depends on:

cholesterol.

Damage to the medial preoptic area of the hypothalamus in rats would most likely result in

decreased sexual activity

If a female rat fetus developed without any alpha-fetoprotein, her hypothalamus would:

develop in a partly masculinized manner.

Wolffian ducts are found in

female and male fetuses early in development.

On average, the left and right hemispheres of the cerebral cortex are of nearly equal size in ____females, whereas the right hemisphere is a few percent larger in _____ males.

hetereosexual, hetereosexual

The suprachiasmatic nucleus is found in the:

hypothalamus.

Compared to REM, research suggests that NREM is:

important for strengthening memories of lists of words.

A couple of paths from the hypothalamus release histamine, thereby:

increasing arousal.

The anterior commissure, on the average, is:

larger in heterosexual women than heterosexual men.

Which of the following is most likely an example of the organizing effects of sex hormones?

masculinization of the brain

Certain genetic males in the Dominican Republic were born with low levels of the enzyme that converts testosterone into dihydrotestosterone. This resulted in:

minimal penis growth early in life.

Congenital adrenal hypertrophy, the most common cause of the intersex condition, occurs when the adrenal gland releases ____ than average levels of the hormone cortisol, causing the hypothalamus and pituitary to release _____ than average levels of ACTH.

more; less

Axons from the locus coeruleus release ____ widely throughout the cortex.

norepinephrine

After a period of sleep deprivation, PGO waves begin to:

occur during sleep stages 2-4 and wakefulness.

During the menstrual cycle, estradiol and progesterone levels increase and decrease under the influence of hormones released by which gland?

pituitary

Organizing effects

produce long-lasting structural effects.During a sensitive period in early development, during the first trimester of pregnancy for humans, sex hormones determine whether the body develops female or male genitals

The SCN produces circadian rhythms by altering:

production of proteins.

Viagra facilitates sexual arousal in males by:

prolonging the effects of nitric oxide.

The ____ is a structure that extends from the medulla into the forebrain.

reticular formation

A small branch of the optic nerve, known as the ____ extends directly from the retina to the SCN.

retinohypothalamic path

Alteration of the per gene in humans is associated with:

shortened circadian rhythms.

With each succeeding stage of sleep (from 1 to 4):

slow, large-amplitude waves increase in number.

A more recent study on differences in the INAH3 suggests that compared to heterosexual men, homosexual men have

smaller INAH3 neurons, but a comparable number

If you were awakened every time you entered REM sleep for a few days, and then were permitted to sleep without interruptions, you would:

spend about 50 percent more time in REM sleep than usual.

Sleep spindles and K-complexes are most characteristic of which sleep stage?

stage 2

According to the activation-synthesis hypothesis, it should be possible to predict (with better than chance accuracy) the content of a person's dreams if we know what information about the person?

stimuli currently acting on the body and areas of spontaneous brain activity

In the middle of the menstrual cycle, an increased release of estradiol causes a(n):

sudden surge in the release of luteinizing hormone.

Most homosexual men, as compared to heterosexual men, have:

testosterone levels within the same range.

Periovulatory period

the days around the middle of the menstrual cycle, when fertility is highest

Patients with damage to ____ report no dreams.

the lower part of the parietal cortex

Psychologists in the early to mid part of the 20th century had difficulty with the notion that wake and sleep cycles were generated from within the body because:

they accepted the theory that all behaviors were responses to stimuli

Psychologists in the early to mid part of the 20th century had difficulty with the notion that wake and sleep cycles were generated from within the body because of _____?

they accepted the theory that all behaviors were responses to stimuli.

The interstitial nucleus 3 of the anterior hypothalamus is known to be more than:

twice as large in heterosexual men as in women.

What is activated by the reticular formation?

wide regions of the entire cerebral cortex

Estrogens directly stimulate parts of the prefrontal cortex that are important for

working memory